Bookmarking items has a variety of uses. Having common items quickly ready to craft, items you frequently forget the recipe for, or even as a sort of checklist. I suggest adding a feature such that you can change pages of the bookmark pane even into empty pages, similar to writing a book in Minecraft. Then, when you bookmark an item, the item gets bookmarked to whatever specific page you have your bookmarks pane set to.

This way you could use the bookmarks for multiple things, have multiple separate item checklists, even with repeated items between pages. As an additional quality of life feature, it would be great to be able to rename the bookmark pages, so you can remember which page is for which set of bookmarks.